Framing mechanism and shutter



Jan. 12, 1943. K. BRENKERT FRAMING MECHANISM AND S HUTTER COMPENSATOR Original Filed Jan. 29, 1940 3 Sheets-Sheet l INVENTOR /far'z, r'e)zerl W ZZQW ATTORNE Y Jan. 12, 1943.

K. B'RENKERT FRAMING MECHANISM ANDsl iUTTER COMPENSATOR Original. F110;! Jan. 29, 19M) '3 Sheath-Shot 2 Y .INVENTOR ar'Z Br-e1 ie rz ATTORNEY Reissued Jan. 12, 1943 FRAMING MECHANISM AND SHUTTER COMIPENSATOR Karl Brenkert, Detroit, Mich, assignor to Brenkert Light Projection Company, Detroit, Mich., a

corporation of Michigan Original No. 2,246,972, dated June 24, 1941, Serial No. 316,176, January 1940. Application for reissue May 29, 1942, Serial No. 445,030

18 Claims.

The present invention pertains to a novel framing mechanism and shutter compensator for motion picture machines, wherein the shutter is compensated automatically during the framing movement.

In motion picture machines, particularly projectors, the pictures or exposures on the film are brought by an intermittent movement successively into register with the projection aperture. The pictures frequently are thrown out of register with the aperture, through various causes well known in the art. The operation of restoring the pictures into register is known as framing.

Framing is commonly performed by rotating the intermittent movement around the axis of the intermittent sprocket, thereby advancing or retarding the film relatively to' the projection aperture, whereby the film is adjusted so that it registers with the projection aperture during the dwell of the intermittent movement. As a result of this adjustment, the relation between the position of the shutter and the dwell of the intermittent is disturbed, and the shutter must therefore be adjusted or compensated to restore its proper synchronism with the intermittent movement. In other words, a fixed static relation between the intermittent movement and the shutter is maintained by effecting an alteration in the static gear relation between the intermittent movement and the shutter drive gearing.

The principal object of this invention is to provide an improved framing mechanism which adjusts the shutter to maintain the timed relation between the movement of the shutter shaft and the sprocket shaft as well as the intermittent mechanism in the manner described above. More specifically, the invention provides a mechanism that is compact, durable and reliable in operation.

Another object of the invention is to maintain the aforementioned timed relation of the shutter, or the compensation, with respect to a double shutter comprising two shutter members rotating in opposite directions. I am not aware that this has prew'ously been done in the prior art.

Another object of; the invention is to effect the compensating gear adjustment at a point remote from the final drive in the shutter gear train, or to avoid making an alteration in the static gear relation at said final drive. In this sense the compensation may be said to occur between the final drive and the intermittent movement. This can be better understood when ,compared with prior constructions wherein the final drive in the shutter gear train consists of two spiral gears in running mesh. The compensation is made by shifting one of these gears relatively to the other. The objection to this arrangement is that the spiral gears do not wear uniformly because of the frequently changing area of contact during framing and compensating. This results in a degree of uneven wear in the running of these gears, which would be eliminated if they could be worn in by running repeatedly on the same contact areas.

Still another object of the invention is to avoid the use of spiral gears in running mesh anywhere in the gear train, for reasons similar to those mentioned above. The invention employs a spline-in the compensating system, and this spline is locked to its next adjacent gear except during the actual framing and compensating adjustment period. This locked condition .is distinguished from the aforementioned running mesh condition wherein one of the gears is driven by the relative rotation of the other, while in the locked condition the gear and spline rotate as a fixed unit and not relatively to each other.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which:

Figure 1 is an elevation of the framing mechanism, showing some of the parts in section;

Figure 2 is a sectional view of the intermittent mechanism in the position corresponding to Figure 1;

Figure 3 is a diagrammatical view of the shutter blades corresponding to the position of parts in Figures 1 and 2;

Figure 4 is a, view similar to Figure 1, illustrating an adjustment of the mechanism;

Figure 5 is a section similar to Figure 2 and corresponding to the position shown in Figure 4, assuming that the driving mechanism has remained stationary during the adjustment;

Figure 6 is a diagrammatic view of the shutter blades corresponding to the position of parts in Figures 4 and 5 under like conditions;

Figure 7 is a section on the line 1-1 of Fig- Figure 8 is a similar section, with certain parts shown in elevation;

' ment in a manner well known in the art and requiring no specific illustration here.

One of these shafts is indicated by the numeral 2 and carries the star wheel 3 of the intermittent Geneva movement as well as the film feeding sprocket. Both members are fixed to the shaft to move together. On the shaft 2 is rotatably mounted a drive sleeve 4 carrying a gear driven from the usual motor by appropriate gearing. Being free on the shaft, the sleeve does not immediately affect the movement of the star wheel and sprocket. The sleeve in turn is loosely surrounded by a boss 6 which is an integral part of a housing 1 enclosing the entire intermittent mechanism.

In the housing I is journaled another shaft 8 carrying a so-called cam consisting of a disk 9 and a pin 59 adapted to enter the slots H of the star wheel 3 after the fashion of the well known Geneva movement. The shaft 8 also carries a gear |2 meshing with the gear 5, whereby the cam is also driven continuously by the motor.

The shaft 8 also carries a lock consisting of of an arcuate member l3 shaped and positioned to engage the arcuate edges I4 of the star wheel when the pin I9 is out of the slot ll, so that the star wheel remains stationary at such times.

The boss 6 is surrounded by a collar I6 fixed at one point I to the housing 1. An arm I8 extends from the collar, and when the arm is moved the housing I is swung in the same direc tion about the stationary axis of the shaft 2, carrying with it the shaft 8 and the cam 9, Ill. The means for thus moving the arm I8 will now be described, and it will be understood in this connection that the adjustment of the cam rela tively to the star wheel is equivalent to pulling the film in one direction or the other and is carried out to the extent necessary to bring the pictures into registration with the projection aperture during the dwell in the intermittent movement.

In a suitable part of the housing is journaled a framing shaft 9 preferably parallel to the sprocket shaft 2. The shaft l9 carries a knob or handle 29 and a sprocket wheel 2|. Adjacent to the shaft I9 is a similarly journaled shaft 22 carrying a preferably larger sprocket wheel 23 joined to the wheel 2| by a sprocket chain 24. A lever 25 is fixed to the shaft 22 to turn therewith through the operation of shaft l9. Below the shaft 22 is another shaft 26 also journaled in the member and about the axis of which is journaled a yoke 21. The latter is joined to the arm 25 by a link 28. .The arm 29 extends rigidly from the yoke and is joined to the arm I8 by the link 30. By this means the cam 9, I0 is adjusted relatively to the star wheel from the knob 20, and a suitable device (not shown) may be provided for locking the knob in its adjusted position.

spline member 38 having a pitch angle of about 49.

Adjacent to the member 38, two more such members 39 and 40 are mounted on the shaft 26 in end to end relation to each other. These members are grooved spirally or splined oppositely to each other and are keyed together at their meeting ends as indicated by the numeral 4| in Figure 8. Next the member 49, a sleeve 42 is mounted on the shaft 26 and secured thereto by a pin 43. The sleeve is slotted lengthwise at 44 to receive a pin 45 extending from a fixed frame member 46. The shaft 25 is thereby held against rotation, but the spline members 39 and 49 are rotatable thereon.

On the member 39 is mounted a gear 4! meshing with another gear 48 co-axial with and fixed I to the crown gear 35, as also disclosed in the above mentioned patent. Similarly a gear 49 is mounted on the member 49 and is in mesh with the divided gear train which is generally repre sented by the numeral 50 and which is branched at 50 to connect with the intermittent gearing 5, l2, the dividing or branching of the gear train being effected by mounting the branch 59 out of mesh with the gearing between the train 59 and the shutter. The gears 41 and 49 are splined internally at 5| to mesh respectively with the spline members 39 and 49. Relative movement between the gears 41 and 49 is possible through the splines, because one gear is free from the shutter drive and the other is free from the intermittent drive.

The yoke 21 terminates in two spaced bosses around the axis of the shaft 26. One of these bosses 52 is adapted to turn freely on the end of the shaft 25 near the pin 43. The other boss 53 is splined internally at 54 to mesh with the member 38, as described in connection with the members 39, 49, 41 and 49. A spacer 55 in the form of a fixed frame member is preferably pro- Adjacent to the axis of the shaft 26 are 7 mounted inner and outer shutter shafts 3| and 32, the inner shaft extending beyond the outer shaft and the ends of the shafts carrying opposed bevel gears 33 and 34. Between these gears is a crown. gear 35 meshing therewith and which, when driven, turns the shafts 3| and 32 in oppo site directions in the manner shown and de scribed in my Patent No. 2,221,364 of August 13, 1940. The remaining ends of the shafts carry vided around the axis of shaft 26 between the members 53 and 41.

When the yoke 21 is turned in the manner described above, the internal spline 54 thereof meshing ,with the spline member 38 causes a sliding movement of this member, the shaft 25 and the members 39, 40, since the slot and pin 45 prevent rotation and permit only longitudinal movement. The sliding of the splines 39 and 40 causes relative rotation of the gears 41 and 49 or, in other words, a change in the static gear relation between the shutter gearing and the gearing of the intermittent mechanism. The main gear train 59 may be considered locked, so that the intermittent receives no direct movement. The parts are so dimensioned that the adjustment of the shutter accurately compensates the loss of synchronism introduced by the framing adjustment of the intermittent mechanism, as above set forth.

Figures 3 and 6 illustrate two relative positions of the shutter blades corresponding to the framing adjustments illustrated respectively in shutter blades 36 and. 31 shown in Figure 4 and illustrated diagrammatically in Figures 3 and 6. F

The shaft 26 is preferably formed in two sections keyed together at 37 for assembly purpose, as shown in Figure 8. One end of the shaft is enlarged in diameter and formed as a multiple Figures 1 and 4, in an assumed static or motionless condition of the driving mechanism. It will be seen that the shutter openings 56 and 51 have been moved from a non-overlapping and fully obstructed position in Figure 3 nearly to the full open position in Figure 6, while the internal spline member 54 has been rotated about The comparatively large movement of the shutter blades is due to the large pitch angle of the several spline members as well as the opposed members 39 and 40 which double the action on the relative displacement of gears 41 and 49, as distinguished from ordinary spiral gears which have a maximum pitch angle of about 14.

The final drive in the shutter gear train comprises the gears 33, 34 and 35, and it is now evident that the compensation results in no. change in the static relation of these gears. Consequently the smoothness derived from running-in are not lost in the compensating operation.

This'fact applies also to the shutter driving gear 41 and the drive gear 49 where they mesh with the multiple splines 39 and 40 respectively. The latter do not normally run against the gears 41 and 49 but rotate bodily therewith except during the compensating action effected through the yoke 21 and the parts 38 and 34. Consequently there is practically no wear on the spline members, and the objection of uneven wear is of course avoided.

Although a specific embodiment of the inveng tion has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is:

1. In a motion picture machine, a shutter shaft, a gear train for driving said shutter shaft and terminating in non-sliding gears, a spiral spline having a measurable area of engagement with one of the gears in said train, means for driving said spline, and means for imparting a limited shift to said spline, whereby said spline and the gear splined thereto remain locked together during normal running by said driving means, said shifting means being adapted to actuate said gear train independently of said driving means.

2. In a motion picture machine, a shutter shaft, a gear train for driving said shafts and terminating in non-sliding gears, an external spiral spline fitted within one of the gears in said train, means for driving said spline, and means for imparting a limited shift to said spline, whereby said spline and the gear splined thereto remain locked together during normal running by said driving means, said shifting means being adapted to actuate said gear train independently of said driving means.

3. In a motion picture machine, a shutter shaft,

a gear train for driving said shutter shaft and terminating in non-sliding gears, an external spiral spline fitted within and having a measurable area of engagement with one of the gears in said train, means for driving said spline and means for imparting a limited shift to said spline,

whereby said spline and the gear splined thereto remain locked together during normal running by said driving means, said shifting means being adapted to actuate said gear train independently of said driving means.

4. In a motion picture machine, a shutter shaft, a gear train for driving said shafts and terminating in non-sliding gears, a spiral spline having a measurable area of engagement with one of the gears in said train, means for driving said spline, a second spline axially alined with the first spline, and rotary shifting means fitted in said first spline in surface engagement therewith, whereby said first spline and the gear splined thereto remain locked together during normal running by said driving means, said shifting means being adapted to actuate said gear train independently of said driving means.

5. In a motion picture machine, an intermittent movement, a final shutter drive gear, a gear train connected tosaid shutter drive gear, a branch gear train extending from the first train to said intermittent movement, means for propelling said train, a" spiral spline attached to an immediate gear in said train, and means for sliding said spline, whereby to effect a movement in said gear train relatively to said intermittent movement driving branch train.

6. In a motion picture machine, an intermittent movement, a final shutter drive gear, a gear train connected to said shutter drive gear, a branch gear train extending from the first train to said intermittent movement, means for propelling said train, a spiral spline attached to an intermediate r gear in said train and normally held against sliding movement, and means for sliding said spline, said movement having an adjustable member linked to said sliding means, whereby to effect a movement in said gear train relatively to said intermittent movement driving branch train.

7. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shutter driving member rotatably and slidably supported thereby, a shutter driving gear spirally splined to said shutter driving member and held against sliding movement, means exclusive of said adjustable member for sliding said shutter driving member relatively to said shutter driving gear, means for rotating said. shutter driving member, and a connection between said sliding means and said adjustable member for adjusting the latter on actuation of said sliding means.

8. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shutter driving member rotatably and slidably supported thereby, a shutter drivinggear surrounding said shutter driving member and spirally splined thereto, means for sliding said shutter driving member relatively to'said shutter driving gear, means for rotating said shutter driving member, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

9. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shutter driving member rotatably and slidably supported thereby, a shutter driving gear spirally splined to said shutter driving member and held against sliding movement, a drive gear spirally splined on said shutter driving member oppositely to said driving gear, both gears being held against sliding movement, means for sliding said shutter driving member relatively to said shutter driving gear, means for rotating said driving member, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

10. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a shutter driving member freely rotatable on said shaft and sliding therewith, means for rotating said shutter driving member, a shutter driving gear spirally splined on said shutter driving member and held against sliding movement, to be adjusted angularly on sliding said shaft and shutter driving member, means for sliding said shaft, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

11. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a shutter driving member freely rotatable on said shaft and slidable therewith, a shutter driving gear spirally splined on said shutter driving member and held against sliding movement, to be adjusted angularly on sliding said shaft and shutter driving member, means for sliding said shaft, a drive gear spirally splined on said shutter driving member oppositely to said driving gear and held against sliding movement, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

12. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a multiple spirally splined shutter dri ing member rotatably and slidably supported thereby, a shutter driving gear surrounding and meshing with said shutter driving member, means for sliding said shutter driving member relatively to said shutter driving gear, means for rotating said shutter driving member, and a connection between said sliding means and said adjustable member for adjusting the latter on actuation of said sliding means.

13. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shutter driving member rotatably and slidably supported thereby, said member having two portions multisplined spirally and oppositely to each other, a shutter driving gear surrounding and meshing with one portion, a drive gear surrounding and meshing with the other portion, both gears being held against sliding movement, means for sliding said shutter driving member relatively to said shutter driving gear, means for rotating said driving member, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

14. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other;'a frame structure, a shaft slidably mounted therein and held against rotation, a shutter driving member freely rotatable on said shaft and slidable therewith, means for rotating said shutter driving member, a shutter driving gear spirally splined on said shutter driving member and held against movement, to be adjusted angularly on sliding said shaft and shutter driving member, an adjusting member rotatably mounted about said shaft and having a spiral spline connection thereto, whereby to slide said shaft, and a connection between said adjusting member and said adjustable member, whereby both are actuated simultaneously.

15. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a multi-spirally splined shutter driving member freely rotatable on said shaft and slidable therewith, means for sliding said shutter drivin member relatively to said shutter driving gear, means for rotating said shutter driving member, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

16. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a shutter driving member freely rotatable on said shaft and slidable therewith, said member having two portions multisplined spirally and oppositely to each other, a shutter driving gear surrounding and meshing with one portion, a drive gear surrounding and meshing with the other portion, both gears being held against sliding movement, means for sliding said shutter driving member relatively to said shutter driving gear, means for rotating said shutter driving member, and a connection between said sliding means and said adjustable member, whereby both are actuated simultaneously.

1'7. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a multi-spirally splined shutter driving member freely rotatable on said shaft and slidable therewith, an adjusting member rotatably mounted about said shaft and havinga spiral spline connection thereto, whereby to slide said shaft, and a connection between said adjusting member and said adjustable member, whereby both are actuated simultaneously.

18. In a motion picture machine, a film feeding mechanism including a constantly rotating drive member and an intermittently rotating member driven thereby, one of said members being mounted for adjustment around the other; a frame structure, a shaft slidably mounted therein and held against rotation, a shutter driving member freely rotatable on said shaft and slidable therewith, said member having two portions multisplined spirally and oppositely to each other, a shutter driving gear surrounding and meshing with one portion, a drive gear surrounding and meshing with the other portion, both gears being held against sliding movement, an adjusting member rotatably mounted about said shaft and having a spiral spline connection thereto, whereby to slide said shaft, and a connection between said adjusting member and said adjustable member, whereby both are actuated simultaneously.

KARL BRENKERT. 

